Toward designing a quantum key distribution network simulation model

As research in quantum key distribution network technologies grows larger and more complex, the need for highly accurate and scalable simulation technologies becomes important to assess the practical feasibility and foresee difficulties in the practical implementation of theoretical achievements. In this paper, we described the design of simplified simulation environment of the quantum key distribution network with multiple links and nodes. In such simulation environment, we analyzed several routing protocols in terms of the number of sent routing packets, goodput and Packet Delivery Ratio of data traffic flow using NS-3 simulator

SarDub19: An Error Estimation and Reconciliation Protocol

Aside from significant advancements in the development of optical and quantum components, the performance of practical quantum key distribution systems is largely determined by the type and settings of the error key reconciliation procedure. It is realized through public channel and it dominates the communication complexity of the quantum key distribution process. The practical utilization significantly depends on the computational capacities that are of great importance in satellite-oriented quantum communications. Here we present SarDub19 error key estimation and reconciliation protocol that improves performances of practical quantum systems

“Who cares about fireworks?” – A Study on Digital Coaching, Gamification and Exercise Motivation

Digital coaching systems offer users support in their physical training through insights and advice based on the individual’s activity data. Often these systems utilize gamification mechanisms to motivate users. In this study we conduct interviews with digital coaching users to understand how digital coaching systems are used to motivate physical activity, what kind of a role gamification plays, and how digital coaching systems should be developed further to better motivate users. We find that data itself is more motivating than gamification mechanisms, that players use data to play their own, internal games; and that data is also used for social purposes. We find that the benefits from digital coaches today are limited and mainly related to accurate exercise tracking and visualization of user data. Gamified elements are used on a low level and not perceived as value-adding by the users; deeper understanding of motivation theory and promoting intrinsic motivation is needed

Modelling of an Expert System for Diagnosing the Operational Status of a Diesel Genset

The modelling of an expert system for diagnosing the operational status of a diesel genset represents the final stage of the research undertaken so far on military gensets. The research was undertaken in several stages on a large number of gensets, and the results obtained at specific research stages were published at scientific-expert conferences. For the purpose of modelling an expert system, a knowledge base was compiled based on detailed observation of the genset operational status, interviews with experts with many years of experience in maintaining military gensets and also on a breakdown of the occurred faults archived in the overhaul documentation.The paper uses only that one segment of the knowledge base that is necessary for modelling a simplified form of the Bayesian network for fault detection in assembled condition. In addition to input probabilities, the results of diagnostic tests and simulations carried out in the Matlab Simulink program package are also entered in the Bayesian network. Fault detection represents a complex process so the application of an expert system significantly reduces the time needed for fault detection, resulting in optimized maintenance. It is especially significant in military and similar organizations which apply a large number of technical resources. The Bayesian network is processed in the GeNIe program package

The 'beating-heart butterfly technique' for repair of basal post-infarction ventricle septum defect

Ischaemic ventricular septal defect is a serious complication of acute myocardial infarction with poor outcome. We present the 'beating-heart butterfly' technique to close the ventricular septal defect with a double-layered pericardial patch sewn to the intact septum under beating-heart cardiopulmonary bypass in 4 highest-risk patients. This technique combined with a liberal postoperative mechanical circulatory support and open-chest treatment allowed excellent results with 12 months of survival in all patients. Keywords: Beating heart; Butterfly technique; Infarction; Surgical repair; Ventricular septal defec

Exploring the Possibilities of Adjusting Gensets to NATO Requirements

Stationary and mobile gensets are used in the Armed Forces of the Republic of Croatia. In this research, priority was given to mobile gensets which have a variety of uses. In addition to being used in the Republic of Croatia, the mobile gensets are also used in international military operations in various modes of operation. Therefore, it is necessary to be very familiar with their characteristics and the possibility of adjusting them to NATO requirements. For the purpose of the adjustment, a test was performed on a P-B40.R1 genset. A model that simulates the genset behaviour with different tested fuels was developed. The investigated genset, together with some others, was introduced into the Armed Forces pursuant to the Product Quality Protocol that was in force during the 1990s. The Protocol did not cover all requirements and recommendations for the genset operation in an international military environment. Therefore, research was conducted, which has resulted in the adjustment of the equipment and in the harmonisation of the Product Quality Protocol with the ISO standard and NATO requirements. When adjusting the materiel, special emphasis is given to defining certain genset types that are able to use the modified F-34 kerosene-type fuel instead of diesel fuel. The F-34 fuel is obtained from kerosene used in aviation; this fuel can be easily obtained in international military operations where the tendency is to use the same type of fuel for airplanes, vehicles, and diesel engine equipment. When F-34 is used as the genset fuel, the quality of the generated electrical energy might be reduced. For the purpose of bringing the output characteristics of the generator within prescribed limits, simulations were performed both with and without the tuning of the regulation parameters